1. Field of the Invention
The present invention relates to a parking aid system, which aids in parking a vehicle into a parking space in a parking lot.
2. Description of Related Art
There is known a technique for aiding a driver in parking a vehicle into a parking space in a parking lot, as described in Japanese Patent No. 4193780 for example. An apparatus described in Japanese Patent No. 4193780 recognizes a parking space boundary provided in a parking lot and calculates an inclination angle of a vehicle with respect to the parking space boundary, based on an image captured by a camera mounted to the vehicle. After the vehicle is moved into the parking space boundary and the parking is finished, and after a gear shifter is changed in a position for forward movement, this apparatus notifies the inclination angle to a driver by using a sound or a synthesized image. In this way, the apparatus can notify the inclination angle of the vehicle with respect to the parking space boundary to the driver.
The inventors of the present application have found that a conventional technique involves the following difficulties.
In some cases, the parking may end up with the following result; although the vehicle is parallel to the parking space boundary, the vehicle may stay in close to one side of the parking space boundary in a width direction of the parking space or the vehicle may straddle one side of the parking space boundary. In other words, a vehicle may be displaced with respect to the parking space boundary in the width direction of the parking space. Since the above conventional technique calculates only the inclination angle of the vehicle with respect to the parking space boundary, it is impossible to notify the driver of the displacement of the vehicle with respect to the parking space boundary in the width direction.
Moreover, according to the above conventional technique, the inclination angle of the vehicle with respect to the parking space boundary is notified after the parking is finished. As a result, if the inclination angle of the vehicle with respect to the parking space boundary is large, the driver may need to retry the parking of the vehicle. There is a room for improvement in preventive measures against this parking retry.